Increased Breast Density Leads To Increased Cancer Risk

Your breast density measurement is probably not something you know off the top of your head like, say, your bra size. But it is a number that could save your life. Numerous studies over the past 40 years consistently show cancer risk to be four to six times higher for women with extremely dense breasts than for women with low density breasts. By comparison, a family history of breast cancer usually only doubles the risk.

Though the scientific community has long agreed with these findings, not much has been done to inform patients because many health professionals are concerned it will only confuse or worry women, since the largest determining factors of breast cancer are uncontrollable (age, heredity and ethnicity). But now, more and more doctors and researchers support reporting breast density measurement (which is recorded during a mammogram) to women, arguing that it might encourage women diagnosed with high density breasts to have more clinical exams and mammograms or MRIs.

“I think patients should be told as much information as possible – recognizing they may not be able to use all of it,” says William Barlow, a senior biostatistician at Cancer Research and Biostatistics in Seattle. “After all, you can’t change most of the risk factors for breast cancer.”

You can, however, keep track of your breast density and any changes over time. Two recent studies reported to the American Association for Cancer Research found that if a woman’s breast density goes up, so does her risk of breast cancer, and vice versa.

One study used data from the 2002 Women’s Health Initiative trial that found postmenopausal women using hormone replacement therapy (HRT) had a greater risk of breast cancer than women who did not use HRT. A newer study compared mammograms done a year apart. Breast density went up for 85 percent of the women in the HRT group, which could explain the increased cancer risk in that group.

This added knowledge may be extremely important in helping a woman decide whether or not she wants to use hormone replacement therapy for the relief of menopausal symptoms.

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July 16, 2010